Writing argumentative paragraphs is challenging even in one's first language (L1) since in order to fulfil their goals writers need to carefully choose among the available metadiscoursive tools and skilfully balance their use. Writing in a foreign language (L2) is even more challenging because language learners are usually familiar only with a limited number of metadiscoursive markers and functions. Therefore, when unsure, these novice L2 writers tend to fall back to old habits and transfer structures from L1 into their L2 texts. However, structures that are acceptable and may even be the norm in L1 may not be appropriate to use in L2. Consequently, the learners may fail to persuade their readers or to communicate their intended message successfully. Since learners with different language backgrounds may have different problems when writing in L2, each group should be studied closely and their specific challenges should be identified and dealt with when teaching academic writing. The aim of this study is to contribute to this specific area of research by, first, identifying and analysing the number and functions of the modal hedges that native speakers of Turkish learning English employ in their L2 argumentative paragraphs and then, to identify the modals whose employment results in a weaker/abrupt and/or inappropriate argumentation. To fulfil these goals argumentative paragraphs written in English by native speakers (NS) of Turkish with pre-intermediate level of proficiency were collected and the modal hedges in these paragraphs were identified and analysed. The findings of the study show that modal hedges in English are a group of markers particularly problematic for second language learners as they are multifunctional, multilayered and culture dependent, and that some of the inappropriate uses or overuses of modals in L2 can stem from the employed teaching materials and/or lack of proper training related to this domain. The results emphasize once again how vital it is to find a place for the metadiscourse markers in the foreign language writing curricula as well in the paragraph assessment rubrics used in the institutions.